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Date:   Wed, 23 Feb 2022 16:57:27 +0530
From:   Viresh Kumar <viresh.kumar@linaro.org>
To:     Lukasz Luba <lukasz.luba@arm.com>
Cc:     Daniel Lezcano <daniel.lezcano@linaro.org>,
        linux-kernel@vger.kernel.org, dietmar.eggemann@arm.com,
        rafael@kernel.org, nm@ti.com, sboyd@kernel.org, mka@chromium.org,
        dianders@chromium.org, robh+dt@kernel.org,
        devicetree@vger.kernel.org, linux-pm@vger.kernel.org
Subject: Re: [PATCH v2 0/2] Introduce 'advanced' Energy Model in DT
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On 23-02-22, 11:22, Lukasz Luba wrote:
> On 2/23/22 10:43, Viresh Kumar wrote:
> > On 23-02-22, 10:52, Daniel Lezcano wrote:
> > > why not extend the energy model to any kind of devices?
> > 
> > FWIW, the OPP core supports a wide range of devices now, not just CPUs.

There are many other devices which still use Freq.

> Is that the "opp-level" thing which would allow that?

For power supplies/regulators, we don't have freq and they use level, right.

Also for interconnect we use bandwidth, in a similar way.

> I can see some DT files with regulators(?) using it e.g. [1].
> It looks flexible, the opp-hz is not hard requirement,
> the opp-level can be used instead IIUC.

Right.

> It might be a next step which might meet Daniel's needs.
> If that 'level' can be any number and frequency is not available
> then EM must have 'level' filed in the struct em_perf_state
> for this kind of new devices. I'm open for such change.
> We can discuss this as a next step. We would need to find some examples
> how this new thing would be used.
> 
> [1] https://elixir.bootlin.com/linux/v5.17-rc5/source/arch/arm/boot/dts/tegra20-peripherals-opp.dtsi#L4

-- 
viresh